Main types¶

The whenever library provides four main date-time types, each with its own purpose and behavior:

The available methods differ between these types based on whether they represent exact time or local time:

type	represents exact time?	represents local time?
`Instant`	✅	❌
`ZonedDateTime`	✅	✅
`OffsetDateTime`	✅	✅
`PlainDateTime`	❌	✅

Exact time methods¶

The exact time classes (Instant, ZonedDateTime, and OffsetDateTime) share several methods for working with exact points in time:

	`Instant`	`ZonedDateTime`	`OffsetDateTime`
`now()`	`🔗`	`🔗`	`🔗`

`timestamp()` [1]	`🔗`	`🔗`	`🔗`
`from_timestamp()` [2]	`🔗`	`🔗`	`🔗`

`to_fixed_offset()`	`🔗`	`🔗`	`🔗`
`to_tz()`	`🔗`	`🔗`	`🔗`
`to_system_tz()`	`🔗`	`🔗`	`🔗`

`x > other_exact` [3]	`🔗`	`🔗`	`🔗`
`x - other_exact`	`🔗`	`🔗`	`🔗`
`x == other_exact`	`🔗`	`🔗`	`🔗`
`exact_eq()`	`🔗`	`🔗`	`🔗`

`x + TimeDelta`	`🔗`	`🔗`	`🔗`

Local time methods¶

The local time classes (PlainDateTime, ZonedDateTime, and OffsetDateTime) share several methods for working with local date and time values:

	`PlainDateTime`	`ZonedDateTime`	`OffsetDateTime`
`year`, `month`, etc.	`🔗`	`🔗`	`🔗`
`hour`, `minute`, etc.	`🔗`	`🔗`	`🔗`
`date()`	`🔗`	`🔗`	`🔗`
`time()`	`🔗`	`🔗`	`🔗`

`replace()` [4]	`🔗`	`🔗`	`🔗`
`add()`, `subtract()`	`🔗`, `🔗`	`🔗`, `🔗`	`🔗`, `🔗`
`since()`, `until()`	`🔗`, `🔗`	`🔗`, `🔗`	`🔗`, `🔗`
`round()`	`🔗`	`🔗`	`🔗`

Note

Although Instant’s debug representation is in UTC, it does not have local time methods. See the FAQ for more details.

Other methods¶

Several other methods are unique to one or more classes:

`Instant`	`ZonedDateTime`	`OffsetDateTime`	`PlainDateTime`
`MIN`, `MAX`			`MIN`, `MAX`
`from_utc()`
`format_rfc2822`		`format_rfc2822()`
	`to_instant()`	`to_instant()`
	`to_plain()`	`to_plain()`
	`offset`	`offset`
			`x == other_plain`
			`x > other_plain`
			`x - other_plain`
			`assume_utc()`
		`assume_tz()`	`assume_tz()`
			`assume_system_tz()`
			`assume_fixed_offset()`
		`parse_strptime()`	`parse_strptime()`
	`tz`
	`now_in_system_tz()`
	`is_ambiguous()`
	`dst_offset()`
	`tz_abbrev()`
	`day_length()`
	`start_of_day()`